This invention relates generally to methods for making scintillator arrays used in radiation detectors, and to the scintillator arrays made from these methods.
In at least one known computed tomography (CT) imaging system configuration, an x-ray source projects a fan-shaped beam which is collimated to lie within an X-Y plane of a Cartesian coordinate system and generally referred to as the xe2x80x9cimaging planexe2x80x9d. The x-ray beam passes through the object being imaged, such as a patient. The beam, after being attenuated by the object, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is dependent upon the attenuation of the x-ray beam by the object. Each detector element of the array produces a separate electrical signal that is a measurement of the beam attenuation at the detector location. The attenuation measurements from all the detectors are acquired separately to produce a transmission profile.
In known third generation CT systems, the x-ray source and the detector array are rotated with a gantry within the imaging plane and around the object to be imaged so that the angle at which the x-ray beam intersects the object constantly changes. A group of x-ray attenuation measurements, i.e., projection data, from the detector array at one gantry angle is referred to as a xe2x80x9cviewxe2x80x9d. A xe2x80x9cscanxe2x80x9d of the object comprises a set of views made at different gantry angles, or view angles, during one revolution of the x-ray source and detector. In an axial scan, the projection data is processed to construct an image that corresponds to a two dimensional slice taken through the object. One method for reconstructing an image from a set of projection data is referred to in the art as the filtered back projection technique. This process converts the attenuation measurements from a scan into integers called xe2x80x9cCT numbersxe2x80x9d or xe2x80x9cHounsfield unitsxe2x80x9d, which are used to control the brightness of a corresponding pixel on a cathode ray tube display.
Detectors of CT and other types of x-ray imaging systems utilize scintillation detectors having pixelated scintillator arrays. It would therefore be desirable to provide simplified, inexpensive methods for making such arrays, and to provide inexpensive, pixelated scintillator arrays for CT and other imaging applications.
To provide simpler, more efficient methods for making scintillator arrays, one embodiment of the present invention is a method for making a scintillator array.
The method includes extruding a mixture of a scintillator powder and a binder into rods; laminating the extruded rods with a sinterable reflector material; and sintering the laminated rods and reflector material into a scintillator block. Scintillator array embodiments of the present invention are useful in many types of pixelated radiation detectors, such as those used in computed tomography systems.